Our vegetable harvests should be in full swing at this point of summer, and I am sure you have noticed a gathering of insects we commonly call stinkbug on your tomatoes as well as bell peppers. You may have seen one to five of them on your veggies about early May and now, by all appearances, the populations are high and appear to be damaging your vegetables. I offer information that will help us understand the form, habit, function and potential control of these unwanted visitors.
Leaf-footed Bug in our Garden
An insect that we commonly call a stinkbug may actually be identified as a leaf-footed bug. The nymph (immature) stages of this insect are soft-bodied with orange to red coloring and what looks like two small black bumps on their backside. You will often see them clustered while feeding on your vegetables. Leaf-footed bug adults are almost an inch long with a gray to brown colored body and a distinctive white band across the front wings. The adult’s hind-legs will have prominent leaf-like bulges, a feature that gives the insect its common name. All stages have piercing-sucking mouth-parts through which they suck plant juices, and feed on a wide variety of developing fruit that includes peaches and tomatoes, as well as seeds such as bean and black-eyed peas. They have been known to feed on stems and tender leaves of some plants.
Leaf-footed bugs overwinter as adults in protected areas, such as in woody brush, barns or other buildings. They lay eggs in spring as the weather begins to warm, nymphs emerge after one week and then begin to develop into adults within five to eight weeks. There are typically two to three generations from the spring through summer. Adults migrate from weedy and brushy areas into vegetable gardens and landscapes, and often when the fruits of your labor begin to ripen.
Their damage is similar to that produced by stinkbugs: on soft-bodied vegetables like tomatoes, the damage initially appears as discoloration to the surface, depressions or blemishes on the fruit. As a result of this activity, you may notice the skin of your tomato plants becoming a little “corky” or tough. The action of puncturing the fruit also allows secondary pathogens access and may be the cause of fruit decline or rotting. Small fruit may abort from the action of feeding, a potential problem for cherry tomatoes such as Sun Gold or Sweet Million. While damage can be a serious issue for commercial fresh market and processing businesses regarding visual appeal and marketability, home gardeners may be able to tolerate minor damage.
Leaf-footed bug populations can fluctuate from year to year due to natural factors such as hard winter freeze that disrupt overwintering, predation of eggs or adults from parasitic wasps, and predation from birds, spiders and assassin bugs. Pre-emptive control can be obtained by removing overwintering sites such as weedy areas. You may also use row covers to keep the critter from accessing the vegetables. Physical removal is also an option especially when the populations are just starting to build. Wear gloves when handling these insects because they will emit an unpleasant odor when crushed or provoked. Insecticides should only be your last line of defense, and are most effective against small nymphs. Broad-spectrum, pyrethroid-based insecticides such as those containing peremethrin can be effective for these insects; these products, however are toxic to bees and beneficial insects and should be used sparingly. I know you have read this next statement from my previous articles: always follow pesticide label application information to the letter, observe the “days-to-harvest” period indicated on the insecticide label, and always wash the fruit before eating. Don’t let a stinky situation get you down; you will still have plenty of vegetables to harvest for your dinner table. I invite you to share successes in your garden by browsing online to my Facebook webpage: www.facebook.com/stephenbhorticulturist.